JPH10228839A - Horn switch mechanism in steering wheel equipped with air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of a horn switch without deteriorating the operability of the horn. SOLUTION: An air bag apparatus 2 is installed under a pad 1 of a steering wheel. A membrane switch 11 is installed between a folded air bag 5 and the pad 1. The membrane switch 11 is mounted and fixed on a switch plate 13 so installed as to cover the air bag apparatus 2. A through hole 1 is formed at a point in approximately center part of the membrane switch 11 and in the switch plate 13, a projected part 16, which is projected toward the pad 1 and is brought into contact with the rear side of the pad 1, is unitedly formed at a position corresponding to the through hole 15. Due to the projected part 16, a constant gap is always kept between the pad 1 and the membrane switch 11 except a time when pushing operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering wheel having an airbag device, and more particularly, to a horn switch mechanism of a steering wheel with an airbag having a membrane switch between a pad and an airbag device. It is.

[0002]

2. Description of the Related Art Conventionally, a steering wheel provided with an airbag device has been known. The airbag device includes a bag holder, an inflator, an airbag, a ring retainer, and the like, and is fixed to a core of a steering wheel. When a predetermined acceleration is applied to the vehicle, nitrogen gas is generated from the inflator,
The airbag breaks the steering wheel pad and inflates and expands.

In a steering wheel provided with an airbag device as described above, a membrane switch is provided between a folded airbag and a pad. The membrane switch is mounted and fixed on a switch plate provided to cover the airbag device. Further, the membrane switch has a pair of thin plates forming a part of the horn switch circuit. When the thin plates contact each other by pressing the pad, the horn sounds based on the contact.

[0004]

However, in the above prior art, the membrane switch is designed so that the membrane switch does not receive the reaction force of the folded airbag and the horn does not sound without a pressing operation. It was necessary to provide a certain gap or more between the pad and the pad.
At this time, it is necessary to set the gap in consideration of the influence of the thermal deformation of the pad.

On the other hand, if the gap is made too large, a problem may arise in that the horn operation is supported. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a horn switch mechanism for a steering wheel including an airbag device, without deteriorating the operability of the horn. It is an object of the present invention to provide a horn switch mechanism of a steering wheel with an airbag which can improve the reliability of the steering wheel.

[0006]

To achieve the above object, according to the first aspect of the present invention, there is provided a pad provided substantially at the center of a steering wheel, and a pad located below the pad and provided with a center of the steering wheel. An airbag device fixed to gold, a switch plate provided below the pad to cover the airbag device, and a lower surface of the pad on the switch plate at a predetermined distance from the lower surface of the pad. A horn switch mechanism of a steering wheel with an airbag which is mounted and fixed and has a membrane switch for sounding a horn when pressed, wherein a slit is provided in the membrane switch and a portion excluding an edge of the switch plate. Is provided with a projection projecting from the slit and contacting the lower surface of the pad. It has as its subject matter that was.

[0007] Here, the slit includes a hole, a notch, and all those that allow the projection to protrude from the switch plate. In the invention according to claim 2,
The gist of the horn switch mechanism for a steering wheel with an airbag according to claim 1, wherein the projection is provided substantially at the center of the switch plate.

According to a third aspect of the present invention, in the horn switch mechanism for a steering wheel with an airbag according to the first or second aspect, the pad has an insert for securing a predetermined rigidity. The gist is that a through hole is provided in a portion of the insert corresponding to the projection.

According to a fourth aspect of the present invention, in the horn switch mechanism for a steering wheel with an airbag according to any one of the first to third aspects, the pad has an insert for securing a predetermined rigidity. In addition, the gist is that the protrusion is provided so as to be movable or elastically deformable in the pressing direction.

Further, according to the invention described in claim 5, a pad provided substantially at the center of the steering wheel, an airbag device located below the pad and fixed to a metal core of the steering wheel, and the pad Below, a switch plate provided so as to cover the airbag device, and mounted and fixed on the switch plate at a predetermined distance from the lower surface of the pad,
A horn switch mechanism of an airbag-equipped steering wheel including a membrane switch for sounding a horn by pressing, wherein a slit is provided in the membrane switch, and a portion excluding an edge of the pad is provided with the slit. The gist of the present invention is to provide a projection that passes through and contacts the upper surface of the switch plate.

(Operation) According to the first aspect of the present invention, when the pad provided substantially at the center of the steering wheel is pressed, it is mounted on the switch plate provided so as to cover the airbag device. The horn switch circuit of the fixed membrane switch comes into contact. This causes the horn to sound.

According to the present invention, a projection protruding from a slit provided in the membrane switch is provided in a portion excluding an edge portion of the switch plate, and the projection abuts on a lower surface of the pad. For this reason, the projection always secures a constant gap between the pad and the membrane switch except during the pressing operation. For this reason, it is possible to set the gap without worrying about reaction force, thermal deformation, dimensional variation, and the like from the airbag.

[0013] According to the second aspect of the invention, in addition to the function of the first aspect, the projection is provided substantially at the center of the switch plate. Therefore, the distance between the strongest edge portion of the pad and the portion corresponding to the protrusion is short. Therefore, the deformation of the pad other than at the time of the pressing operation is minimized, and the gap is more reliably secured.

According to the third aspect of the invention, in addition to the effects of the first and second aspects of the invention, the pad has an insert, so that a predetermined rigidity is ensured. In addition, with the provision of the insert, there is a concern that the horn switch may be activated when a portion corresponding to the protrusion is pressed, but in the present invention, a portion of the insert corresponding to the protrusion is transparent. A hole is provided. Therefore, even when a portion corresponding to the projection is pressed, the pad at that portion can be elastically deformed. Therefore, even in such a case, the horn switch circuit of the membrane switch can be brought into contact.

According to the fourth aspect of the present invention, in addition to the functions of the first to third aspects, the pad has an insert, so that a predetermined rigidity is ensured. Also, as described above, by providing the insert, there is a concern that the horn switch is activated when the portion corresponding to the protrusion is pressed, but in the present invention, the protrusion is movable in the pressing direction. Alternatively, it is provided so as to be elastically deformable. For this reason, even when the portion corresponding to the projection is pressed, it can move or elastically deform in the pressing direction. Therefore, even in such a case, the horn switch circuit of the membrane switch can be brought into contact.

Further, according to the invention described in claim 5,
Basically, an operation equivalent to the operation of the first aspect of the present invention can be obtained only by different positions of the projections.

[0017]

As described above in detail, according to the horn switch mechanism of the steering wheel with an airbag of the present invention, the reliability of the horn switch can be improved without deteriorating the operability of the horn. It has an excellent effect that it can be done.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, approximately in the center of the steering wheel,
A pad 1 made of an elastic synthetic resin material such as polyurethane is provided. Below the pad 1, an airbag device 2 is provided. As is well known, the airbag device 2 includes a bag holder 3, an inflator 4, an airbag 5,
And a ring retainer 6 and the like. The metal bag holder 3 is fixed to a metal core (not shown) of the steering wheel. An opening portion of the bag holder 3 has an inflator 4 containing a gas generating agent therein.
Are arranged. Also, on the upper surface of the inflator 4,
An airbag 5 made of cloth and a ring retainer 6 made of metal are attached. More specifically, ring retainer 6
Are integrally formed with a plurality of legs 7 projecting downward. Then, these legs 7 are inserted into the through holes of the airbag 5, the bag holder 3 and the inflator 4, and
The nut 8 is fastened to the screw portion of the leg 7 projecting from the lower side of the inflator 4, so that the inflator 4
The airbag 5 and the ring retainer 6 are attached and fixed to the bag holder 3.

When a predetermined acceleration is applied to the vehicle, nitrogen gas is generated from the inflator 4, and the airbag 5 breaks the pad 1 and inflates and expands. The pad 1 has a notch 9 for facilitating expansion of the pad 1 when the airbag 5 is inflated.

In the present embodiment, as shown in FIGS. 1 and 2, a membrane switch 11 is provided between the folded airbag 5 and the pad 1. The membrane switch 11 is mounted and fixed on a switch plate 13 provided so as to cover the airbag device 2. The switch plate 13 is made of thermoplastic polyolefin, and is fixed to the bag holder 3 or the like.

The membrane switch 11 has a pair of thin plates forming a part of a horn switch circuit. A printing spacer 1 for securing a constant gap between a pair of thin plates
4 are formed so that the thin plates do not contact each other except during the pressing operation. When the thin plates contact each other by pressing the pad 1,
The horn sounds based on the contact.

In the present embodiment, a through hole 15 as a slit is formed at one location substantially at the center of the membrane switch 11. Also, the switch plate 13
Among them, a projection 16 protruding toward the pad 1 is integrally formed at a portion corresponding to the through hole 15. The projection 16 is in contact with the back surface of the pad 1.

Next, the operation and effect of this embodiment will be described. In the present embodiment, when the pad 1 is pressed, the horn switch circuit of the membrane switch 11 comes into contact. This causes the horn to sound. In addition, in the present embodiment, the switch plate 13 is provided with the protrusions 16 as described above,
The protrusion 16 contacts the lower surface of the pad 1. For this reason,
Due to the projections 16, the pad 1 is always kept except when pressing.
In addition, a certain gap is secured between the membrane switches 11. Therefore, the reaction force from the airbag 5 and
The gap can be set without worrying about thermal deformation of the pad 1 and variation in dimensions. As a result, the reliability of the horn switch can be improved without deteriorating the operability of the horn. The pad 1 is made of an elastically deformable material. Therefore, even if a portion of the pad 1 corresponding to the projection 16 is pressed, the pad 1 itself can be elastically deformed by the pressing operation. Therefore, even in such a case, the horn switch circuit of the membrane switch 11 can be brought into contact. As a result, operability can be further improved. In addition, the protrusion 16 is provided substantially at the center of the switch plate 13. Therefore, among the pads 1,
The distance between the strongest edge and the portion corresponding to the projection 16 is short. Therefore, the deformation of the pad 1 other than at the time of the pressing operation is minimized, and the clearance is more reliably secured. As a result, operability can be ensured, and the reliability of the horn switch can be further improved.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. However, in the present embodiment, since the basic configuration is the same as the above-described first embodiment,
About the same member, the same code | symbol is attached | subjected and the description is abbreviate | omitted, and below, it demonstrates centering around a difference.

As shown in FIG. 3, the pad 1 according to the present embodiment is provided with an elastically deformable pad body 1a made of foamed polyurethane or the like, and provided inside the pad body 1a to secure a predetermined rigidity of the pad 1. And an insert 1b made of polypropylene.

As shown in FIGS. 3 to 5, the membrane switch 21 includes a pair of copper thin plates 22, a PET film 23 for covering the thin plates 22, and a printing spacer 24. Membrane switch 2 in the present embodiment
1 is configured by bending a line-symmetric one. Thereby, when folded, the printing spacers 24 face each other at the same position, so that the printing spacers 24 are doubled.
A large gap between the two can be secured.

Further, as shown in FIG. 3, also in this embodiment, the membrane switch 21 is provided with a through hole 25 as a slit, and the switch plate 13 projects from the through hole 25. The projection 26 is formed integrally. The protrusion 26 of the insert 1b
Is formed in a portion corresponding to the above, and the projection 26 is in contact with the pad body 1a of the pad 1.

In the present embodiment, since the pad 1 has the insert 1b, a predetermined rigidity is ensured. In addition, the presence of the insert 1b may cause the horn switch to be activated when the portion corresponding to the protrusion 26 of the pad 1 is pressed, but in the present embodiment, the horn switch is one of the inserts 1b. A through hole 27 is provided in a portion corresponding to the projection 26. Therefore, even when a portion corresponding to the projection 26 is pressed, the pad 1 (pad body 1a) at that portion can be elastically deformed. Therefore, even in such a case, the membrane switch 2
One horn switch circuit can be brought into contact, and the reliability of the horn switch can be improved.

The embodiment is not limited to the above, but may be modified as follows. (1) In the above embodiments, the switch plate 13 is provided with one projection 16, 26. However, as shown in FIG. 6, a plurality of (three in the figure) projections 31, 32, 33 are provided.
May be provided.

(2) In the second embodiment, when the pad 1 has the insert 1b, the through hole 27 is provided in a portion of the insert 1b corresponding to the projection 26. On the other hand, as shown in FIG. 7, a portion around the protrusion 35 of the switch plate 34 may be formed to be thin and elastically deformable. With such a configuration, the protrusion 35 is pressed in the pressing direction of the pad 1 (the vertical direction in the drawing)
Therefore, even when a portion corresponding to the projection 35 is pressed, the membrane switch 1
It is possible to make the horn switch circuits of 1, 21 contact each other.

Further, the projection itself may be elastically deformable. (3) Although not described in the above embodiment, the membrane switch may be provided with a slit, and the pad 1 may be provided with a projection that passes through the slit and abuts on the upper surface of the switch plate. . Even with such a configuration, the above-described operation and effect can be ensured.

(4) In the above embodiment, the through holes 15 and 25 are provided as slits, but may be notches.

[Brief description of the drawings]

FIG. 1 is a sectional view of a pad and the like for explaining a horn switch mechanism according to a first embodiment.

FIG. 2 is a plan view of a membrane switch and the like.

FIG. 3 is a sectional view of a pad and the like for describing a horn switch mechanism according to a second embodiment.

FIG. 4 is a plan view for explaining a configuration of a membrane switch.

FIG. 5 is a schematic sectional view of a membrane switch.

FIG. 6 is a plan view showing another embodiment.

FIG. 7 is a cross-sectional view of a main part showing another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pad, 1b ... Insert, 2 ... Airbag device,
5 ... airbag, 11, 21 ... membrane switch, 1
3, 34: switch plate, 15, 25: through holes as slits, 16, 26, 31, 32, 33, 35: projections, 27: through holes of insert.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akio Hosoi 1 Ochiai, Nagahata, Kasuga-cho, Nishi-Kasugai-gun, Aichi Prefecture Toyoda Gosei Co., Ltd. Address Toyoda Gosei Co., Ltd.

Claims (5)

[Claims] A pad provided substantially at the center of the steering wheel; an airbag device located below the pad and fixed to a core of the steering wheel; and an airbag device below the pad. A switch plate provided so as to cover, and an airbag provided with a membrane switch mounted and fixed on the switch plate at a predetermined distance from the lower surface of the pad and sounding a horn by pressing A horn switch mechanism for a steering wheel, wherein a slit is provided in the membrane switch,
A horn switch mechanism for a steering wheel with an airbag, wherein a projection protruding from the slit and abutting on a lower surface of the pad is provided in a portion excluding an edge of the switch plate. 2. The horn switch mechanism for an airbag-equipped steering wheel according to claim 1, wherein the projection is provided substantially at the center of the switch plate. 3. The pad according to claim 1, wherein the pad has an insert for securing a predetermined rigidity, and a portion of the insert corresponding to the projection has a through hole. Or a horn switch mechanism for a steering wheel with an airbag according to 2. 4. The pad according to claim 1, wherein the pad has an insert for ensuring predetermined rigidity, and the projection is provided so as to be movable or elastically deformable in a pressing direction. 4. The horn switch mechanism for a steering wheel with an airbag according to any one of 3. 5. A pad provided substantially at the center of a steering wheel; an airbag device located below the pad and fixed to a core of the steering wheel; and an airbag device below the pad. A switch plate provided so as to cover, and an airbag provided with a membrane switch mounted and fixed on the switch plate at a predetermined distance from the lower surface of the pad and sounding a horn by pressing A horn switch mechanism for a steering wheel, wherein a slit is provided in the membrane switch,
A horn switch mechanism for a steering wheel with an airbag, characterized in that a projection that passes through the slit and abuts on an upper surface of the switch plate is provided in a portion other than an edge of the pad.